Buggy code:
class AddFolderToIndex extends IndexRequest { IPath folderPath ; IProject project ; char [ ] [ ] inclusionPatterns ; char [ ] [ ] exclusionPatterns ; public AddFolderToIndex ( IPath folderPath , IProject project , char [ ] [ ] inclusionPatterns , char [ ] [ ] exclusionPatterns , IndexManager manager ) { } public boolean execute ( IProgressMonitor progressMonitor ) { if ( ( this . isCancelled ) || ( ( progressMonitor != null ) && ( progressMonitor . isCanceled ( ) ) ) ) return true ; if ( ! ( project . isAccessible ( ) ) ) return true ; IResource folder = this . project . getParent ( ) . findMember ( this . folderPath ) ; if ( ( folder == null ) || ( ( folder . getType ( ) ) == ( IResource . FILE ) ) ) return true ; Index index = manager . getIndex ( this . containerPath , true , true ) ; if ( index == null ) return true ; ReadWriteMonitor monitor = index . monitor ; if ( monitor == null ) return true ; try { monitor . enterRead ( ) ; final IPath container = this . containerPath ; final IndexManager indexManager = this . manager ; if ( ( ( this . exclusionPatterns ) == null ) && ( ( this . inclusionPatterns ) == null ) ) { folder . accept ( new IResourceProxyVisitor ( ) { public boolean visit ( IResourceProxy proxy ) { if ( ( proxy . getType ( ) ) == ( IResource . FILE ) ) { if ( Util . isJavaFileName ( proxy . getName ( ) ) ) indexManager . addSource ( ( ( IFile ) ( proxy . requestResource ( ) ) ) , container ) ; return false ; } return true ; } } , IResource . NONE ) ; } else { folder . accept ( new IResourceProxyVisitor ( ) { public boolean visit ( IResourceProxy proxy ) { switch ( proxy . getType ( ) ) { case IResource . FILE : if ( Util . isJavaFileName ( proxy . getName ( ) ) ) { IResource resource = proxy . requestResource ( ) ; if ( ! ( org . eclipse . jdt . internal . core . util . Util . isExcluded ( resource , inclusionPatterns , exclusionPatterns ) ) ) indexManager . addSource ( ( ( IFile ) ( resource ) ) , container ) ; } return false ; case IResource . FOLDER : if ( org . eclipse . jdt . internal . core . util . Util . isExcluded ( proxy . requestResource ( ) , inclusionPatterns , exclusionPatterns ) ) return false ; } return true ; } } , IResource . NONE ) ; } } catch ( CoreException e ) { if ( JobManager . VERBOSE ) { <START_BUG> JobManager . verbose ( ( ( "-><seq2seq4repair_space>failed<seq2seq4repair_space>to<seq2seq4repair_space>add<seq2seq4repair_space>" + ( this . folderPath ) ) + "<seq2seq4repair_space>to<seq2seq4repair_space>index<seq2seq4repair_space>because<seq2seq4repair_space>of<seq2seq4repair_space>the<seq2seq4repair_space>following<seq2seq4repair_space>exception:" ) ) ; <END_BUG> e . printStackTrace ( ) ; } return false ; } finally { monitor . exitRead ( ) ; } return true ; } public String toString ( ) { } }

Fix:
org . eclipse . jdt . internal . core . util . Util . verbose ( ( ( "-><seq2seq4repair_space>failed<seq2seq4repair_space>to<seq2seq4repair_space>add<seq2seq4repair_space>" + ( this . folderPath ) ) + "<seq2seq4repair_space>to<seq2seq4repair_space>index<seq2seq4repair_space>because<seq2seq4repair_space>of<seq2seq4repair_space>the<seq2seq4repair_space>following<seq2seq4repair_space>exception:" ) , System . err ) ;